Can someone more technically minded please explain to me what the differences between the TF and the TH are in these pics. What are the extra vacuum pipes (well what looks to be vacuum pipes to me) on the TH for or am I missing something? Might be obvious to some but unfortunately not to me. I wont be back online till 10pm, but thanks in advance. Cheers Neil.

http://neilk.customer.netspace.net.au/tfeng.jpghttp://neilk.customer.netspace.net.au/theng.jpg

p.s. thanks mysti for the engine pic

thats the intake manafold isnt it? and there are 6 pipes on each one for each cyclinder. The engines are exactally thing same i think (assuming they are both 3ltr varients.)

That's the plenum. The inlet manifold connects it to the heads. He's asking about the extra tubes and stuff on the right hand one.

That is correct, looks like a form of vacuum system. Just curious what it is and what it does?
Anyone?

The answer my friend is blowing in the wind. :nuts: sorry

According to my trusty manual one is the exhaust gas recirculation (EGR) solenoid and the other Evaporative emmission purge solenoid EEPS.

EGR reduces the nitrogen oxide emmisions caused by high combustion Temperatures by feeding back a little exhaust into the inlet reducing combust temp. you think itd make it hotter :confused:

EEPS this basicaly stops fuel vapour from the tank venting to atmosphere, this system takes the vapour from the tank and feeds it into the Throttle body.

I wouldn't worry about the differences unless other TFs have them as car manufacturers change polution setups like their socks :pray:, mmmm that should be daily

Hey, Thanks philsTH for the info. Makes sense now. :thumbsup:
Sounds like it could raise the mixture temp in the chamber during the intake stroke. I wonder during compression, if the warmer air assists or hinders combustion? I would have thought it may hinder more than anything making combustion sluggish, (assuming warmer air is easier to compress) which would be a pretty typical trait of emission control. Though on the flip side it may slightly reduce cylinder and piston wear over the long term?!?
I would like to think that the EEPS balances the equation out a bit given it has more fuel vapour content compared to say the TF than air, thus potentially assisting ignition response.
I could be talking out of my :booty: but I am trying to work it out!
Cheers again, Neil.

Engine on left - 3.0L
Engine on right - 3.5L
Yes, vac tubing is for exhaust gas recirculation control, and fuel canister purge for fumes from the fuel tank. 3.0L does not have EGR.